The United States currently has the largest number of older adults at any time in its history, and this number is expected to rapidly increase over the next 20 years. This rapid increase in the aged population highlights the need to better understand changes that accompany aging and which may contribute to mental health and well-being in later life. One important and relatively unexplored aspect of aging relates to the changes that occur with decision making in the social and emotional realms. Making the correct social and emotional decisions during the lifespan is an essential contributor to well-being. One model that describes social and emotional flourishing with aging is Socioemotional Selectivity theory. According to Socioemotional Selectivity theory, there is an increasing focus on positive emotion over the adult lifespan such that older individuals selectively choose social interactions where the likelihood of positive emotional experience is high. In this setting, social contacts are limited to good friends and family, and greater satisfaction and well-being is achieved while the number of social contacts decreases. The underlying neural mechanisms that support this enhanced Socioemotional decision-making have received relatively little attention, but are important as they may protect from social isolation and mental illness. The specific purpose of the current proposal is to examine how the brain correlates of two well defined aspects of Socioemotional decision making - primary appraisal and affective learning about social objects (i.e., people) - are altered with aging. We will focus on two specific brain areas involved in these decision-making processes, the ventromedial prefrontal cortex and the amygdala. We plan to collect and analyze structural and functional magnetic resonance imaging data and self-report measures of social network characteristics and well-being. The overarching hypothesis is that age-related differences in ventromedial prefrontal cortex-amygdala circuitry during Socioemotional decision- making are closely related to Socioemotional selectivity and well-being in aging. Aim 1 will investigate age-related changes in the structure-function relationships between the ventromedial prefrontal cortex and amygdala during different aspects of Socioemotional decision making. Aim 2 will investigate how the ventromedial prefrontal cortex-amygdala circuitry relates to social network characteristics and well-being across the lifespan. The results of these studies will elucidate the neural bases of healthy Socioemotional decision-making and well-being in aging.